In May, Porsche's U.S. chief, Detlev von Platen, called for the brand, including its dealers, to improve customer satisfaction ratings.

GM still near top

For the second consecutive year, General Motors brands dominated three of the four top spots among mass-market brands.

Despite a 19-point decline from last year’s score, Buick placed just behind Mini for a third straight year. It scored 707. Buick was followed by Chevrolet, GMC, Volkswagen, Fiat, Ford, Hyundai, Mazda and Subaru, all of which scored above the mass-market brands’ average of 681.

The biggest tumble was by Toyota, which fell from No. 6 to below the mass-market brand average, scoring 678. Honda beat Toyota by one point at 679.

Overall, sales satisfaction improved to 688 in 2015 from 686 last year.

With more and more tech-savvy customers, those dealerships that integrated technology tools into their sales process delivered a superior customer experience, the study found.

For example, among luxury and non-luxury brands, salespeople who used tablets to record customer vehicle needs, demonstrate car features and display pricing information earned higher satisfaction scores than those who did not use a tablet. Notably, the use of handwritten price quotes had a negative impact on buyer satisfaction with technology usage.

“Dealerships should understand that customers want and trust technology and that it can enhance efficiencies,” Chris Sutton, vice president of the automotive retail practice at J.D. Power, said in a statement. “Dealers that disregard it may risk being left behind in three to five years.”

Finance and insurance products also impacted scores. The J.D. Power survey’s results showed that among non-luxury owners, satisfaction is 46 points higher when a dealer offers them a prepaid maintenance contract vs. when they do not. Among luxury owners, the gap is 26 points. And when those F&I products are presented on a computer tablet, satisfaction is even higher vs. printed materials or verbal descriptions and handwritten materials.

Salesperson influence

The most important key performance indicator in the sales process continues to be the salesperson’s ability to completely understand the customer’s needs, J.D. Power said. The measure is met 86 percent of the time and, when met, it can boost overall satisfaction by up to 106 points.

J.D. Power said high-scoring salespeople are “good listeners, ask relevant questions and are able to deliver on customer requests.”

Sales Satisfaction Index Ranking Luxury Brands

(Based on a 1,000-point scale)

Porsche

752

Mercedes-Benz

749

Lexus

741

Infiniti

739

Jaguar

739

Cadillac

738

Luxury Brand Average

732

BMW

731

Lincoln

731

Audi

728

Land Rover

710

Volvo

708

Acura

706

Sales Satisfaction Index Ranking Mass Market Brands

(Based on a 1,000-point scale)

Mini

762

Buick

707

Chevrolet

701

GMC

697

Volkswagen

691

Fiat

689

Ford

688

Hyundai

683

Mazda

683

Subaru

682

Mass Market Brand Average

681

Honda

679

Toyota

678

Nissan

676

Chrysler

666

Ram

664

Kia

662

Mitsubishi

662

Dodge

652

Jeep

651

Note: Scion is included in the study, but not ranked due to small sample size. Smart is included in the study, but not ranked due to insufficient sample size.

Source: J.D. Power 2015 U.S. SSI Study

The 2015 U.S. Sales Satisfaction Index Study, now in its 29th year, is based on responses from 27,831 consumers who bought or leased a new vehicle in April or May 2015.

It measures satisfaction with the sales experience among new-vehicle buyers and so-called rejecters -- those who shop a dealership but purchase a new car or light truck elsewhere.

J.D. Power calculates the buyer-satisfaction scores using four factors, in this order of importance: Working out the deal; salesperson; delivery process; and facility.

Rejecter satisfaction is based -- also in order of importance -- on the salesperson; fairness of price; experience negotiating; variety of inventory; and facility.